Of course, but a liquid lead reactor's failure modes don't usually involve a massive release of radioactivity all over the environment. Absolute worst case you'

Of course, but a liquid lead reactor's failure modes don't usually involve a massive release of radioactivity all over the environment. Absolute worst case you'll get a meltdown and/or a coolant leak. But diligent materials choices should prevent an associated fire or steam explosions that would spread radioactive elements all over the place. This isn't true with all liquid metal reactors though. Liquid sodium reactors have flammable radioactive coolant, and a coolant breach could be environmentally disastrous.